There are three schools of thought.
One is that a dog doing that needs a multivitamin so if you want to throw him a children's Flintstone a day you could.
Another school of thought is that the poop he is consuming still has nutrients in it so you would sprinkle the dogs diets with “Adolph's meat tenderizer” to aid with complete digestion in the dog that seems to be the victim of his copraphagia.
The last three schools of thought, would be to
- either live with it,
- hope he grows out of it,
- put a static training collar on him and give him a correction whenever he goes after someone's poop.